\begin{tikzpicture}
    \tkzDefPoints{0/0/O, 4/0/A, 3/3/B,  0/1.5/M, 4/1.5/N}
    \tkzDrawSegments(O,A  O,B  M,N)
    \tkzLabelPoints[below](O,A)
    \tkzLabelPoints[left](B)
    \tkzLabelPoints[above](M,N)
\end{tikzpicture}

